In agriculture, augers are frequently used to move an agricultural material from a cart to another cart, silo, truck, or other storage facility. A typical auger for a grain cart includes an auger screw that is housed inside a tubular housing. An intake portion of the auger assembly can draw from a hopper (usually by gravity) attached to it to receive grain or other material from the hopper and the other end (i.e., the discharge end) has a chute or the like to guide the grain or other material into its destination.
As a grain cart with a fully extended auger can be somewhat unwieldy during transport, many grain carts employ folding augers that can open to an operating position and fold to a transport position. In general, a folding auger assembly includes a lower auger assembly and an upper auger assembly, in which the upper auger assembly moves with respect to the lower auger assembly between the operating position and the transport position. Accordingly, folding augers typically include a coupling assembly disposed at a junction between the upper and lower auger assemblies and received in the tubular housing, whereby the coupling assembly allows one end of the lower auger screw to releasably connect to one end of the upper auger screw when the auger assembly is in the operating position.
However, the coupling assembly typically includes several components in order to translate rotation of the lower auger screw to the upper auger screw while keeping the auger screws intact. Consequently, void space is provided between the ends of the auger screws to afford sufficient room for all the components of the coupling assembly. Moreover, as augers have increased in size over the years to provide a greater throughput, coupling assemblies have increased in size, as well, by including more components, such as, for example, a flexible connector. Accommodating room for the coupling assembly in the auger assembly, especially for coupling assemblies with several components, increases the void space between the adjacent ends of the upper and lower auger screw. A higher volume of grain material tends to collect in that increased void space between the upper and lower auger assemblies compared to other areas of the auger assembly. The buildup of grain material at the junction between the upper and lower auger assemblies causes higher grain pressure pushing on the auger flighting edge, thereby resulting in a higher wear rate on the auger flighting edge.
Past practices addressed the problem of increased flighting wear by welding more material to the edge and/or face of the flighting or applying a wear resistance material to the surface of the flighting. However, welding more material or applying a wear resistance material increases the cost, the complexity, and the labor demand for the manufacturing process of the auger assembly. In particular, it has been challenging to weld a strip of metal to the edge of the blade where the metal strip matches the profile and shape of the flighting. Another problem is that the welded strips cannot be replaced without replacing the entire section of flighting when servicing the metal strip for repair.
Another common approach to increase flighting life is fastening plastic shoes to the auger flighting. However, the plastic shoes are typically not strong enough to be installed on the flighting without further support. Moreover, helical flighting predominantly made of plastic are typically incorporated in smaller-sized augers that operate at lower speeds (e.g., less than 500 RPM). Plastic flighting tends to deflect more as the speed of the auger increases. Auger assemblies for common sized grain carts operate at higher RPM's to expedite the unloading time. Incorporating plastic flighting in each section of an auger assembly for a grain cart would hinder the balancing the auger assembly, as the junction between the sections would result in greater deflection.
Furthermore, it is generally desirable to employ augers that move grain as quickly as possible (i.e., to employ augers that have high throughput). To increase the throughput, the diameter of the auger tube and auger flighting have been increased so that the auger assembly may handle a greater volume of grain. However, increasing the diameter of the auger tube and flighting results in more grain material in the void space between the adjacent ends of the upper and lower auger screw. The higher volume of grain material stuck between the ends of the upper and lower auger screws tends to be lifted by the lower auger assembly repeatedly without being captured by the upper auger assembly, thereby increasing the torque demand by the auger assembly to convey the grain material through the auger assembly. In addition, grain stuck at the junction between the upper and lower auger assemblies tends to drop to the ground when the auger assembly folds back to the transport position, resulting in a loss of grain material.